Toy building block



FIG. 1 is a front perspective view of a toy building block embodying our design;

FIG. 2 is a bottom perspective view of FIG. 1;

FIG. 3 is a side view of FIG. 1;

FIG. 4 is a side view of FIG. 3 rotated 90 degrees;

FIG. 5 is a side view of FIG. 4 rotated 180 degrees;

FIG. 6 is a top plan view of FIG. 1; and,

FIG. 7 is a bottom view of FIG. 1.

The broken lines illustrate a portion of a toy building block that forms no part of the claimed design. 

CLAIM We claim the ornamental design for a toy building block, as shown and described. 